<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            height: 300px;
            width: 600px;
            box-sizing: border-box;
            display: grid;
            grid-template-columns: repeat(6,1fr);
            grid-template-rows: repeat(3,1fr);
            gap: 3px 3px;
        }
        .inner{
            width: 100px;
            height: 100px;
            line-height: 100px;
            text-align: center;
            box-sizing: border-box;
            border: 1px solid #000;
        }
        .inner:nth-child(1){
           background-color: orange;
        }
        .inner:nth-child(2){
            grid-column-start: 2;
            grid-column-end: 4;
            width: 100%;
            background-color: purple;
        }
        .inner:nth-child(3){
            grid-column-start: 4;
            grid-column-end: 6;
            width: 100%;
            background-color: yellowgreen;
        }
        .inner:nth-child(4){
           background-color: yellow;
        }
        .inner:nth-child(5){
           background-color: rgba(255, 217, 0, 0.833);
        }
        .inner:nth-child(6){
            grid-column: 2/4;
            width: 100%;
           background-color: green;
        }
        .inner:nth-child(7){
            grid-column: 4/6;
            width: 100%;
           background-color: palevioletred;
        }
        .inner:nth-child(8){
           background-color: blue;
        }
        .inner:nth-child(9){
           background-color: plum;
        }
        .inner:nth-child(10){
           background-color: #0073ffc7;
        }
        .inner:nth-child(11){
            grid-column: 3/5;
            width: 100%;
           background-color: #003180d4;
        }
        .inner:nth-child(12){
           background-color: pink;
        }
        .inner:nth-child(13){
           background-color: yellow;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
        <div class="inner"></div>
    </div>
</body>
</html>